#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=2e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
int main(void){
   	cin.tie(0);std::ios::sync_with_stdio(false);
    LL k;cin>>k;
    string a,b;cin>>a>>b;
    LL num1=0;LL num2=0;
    for(LL i=0;i<a.size();i++){
        num1=num1*k+(a[i]-'0');
    }
    for(LL i=0;i<b.size();i++){
        num2=num2*k+(b[i]-'0');
    }
    cout<<num1*num2<<endl;
   	return 0;
}
